[gofast2wheeler]

I was wondering if someone knows if you have to purchase a Deda stem when using one of their bars. Their bars measure 31.7 not the usual 31.8 3T uses. Are they interchangeable with each other or is it best to use same make for both stem and bar?

Mar

 

[looigi]

Yes. I have a 3T stem and Deda bar. The difference is nominal measurement 0.1 mm (.004") is less than the variation in actual individual parts.

 

[wim]

Nominal 31.7 mm and 31.8 mm are interchangeable. The actual standard is 1-1/4 inch, which converts to 31.75 mm. In a clever (or stupid, depending on your point of view) marketing ploy, Deda chose to call that dimension "31.7" instead of the "31.8" everyone else uses. Didn't see looigi's post, what he says.

 

[Kerry Irons]

I was wondering if someone knows if you have to purchase a Deda stem when using one of their bars. Their bars measure 31.7 not the usual 31.8 3T uses. Are they interchangeable with each other or is it best to use same make for both stem and bar?

31.7 mm is actually 31.75 (1.25 inches from mountain bike standard). 31.8 mm is acutally 31.75. They are identical.

Rounding rules say you should call 31.75 31.8 if you go with only three significant figures, but the "31.7 guys" probably just truncate.

 

[dcgriz]

^^^^ this